People treat coolers like they're buying a truck when they're really buying a hammer. The real test is how the hinges and latches hold up after two years of being tossed around, not whether it floats or stops a bear. I've had cheap coolers crack at the drain plug on a hot day in the desert, and that's the quiet death nobody talks about. The expensive ones usually fail the same way, just slower and with a bigger price tag. If you're not hauling fish or meat for days, the sticker price is mostly about peace of mind, and that's fine, but don't pretend it's science. My advice is to check the latch design before you buy anything, that's the first thing to give out on every cooler.
...so my buddy bought one of those fancy rotomolded ones after his Igloo gave up the ghost on a week-long trip. Thing is, the new one's latch busted off on day three when he slammed it shut with one hand. He spent the rest of the trip bungee-cording it closed, same as the cheap one he had before.